1. Field of the Invention
The invention deals with electrical switches, and more particularly, with multiple function electrical switches that can be placed in a single, standard gang box.
2. Description of the Prior Art
As the use of electrical equipment in the home and commercial establishments increases, there is a need to increase the number of electrical switches used for controlling or supplying electrical power to such equipment. However, much of this equipment is placed in existing structures where it is difficult to increase the number of gang boxes in which such switches can be placed or increase the number of electrical cables extending through existing walls. To provide adequate heat dissipation and to insure that all equipment is properly connected to a neutral return conductor, the number of switch devices or receptacles in each box is limited and each cable that provides electrical power to such switches and receptacles must also contain the neutral return conductor.
At present, triple rocker switches are available, each providing a single pole, single throw on-off switch and requiring two conductors for each switch unit. Thus, there are six conductors crowded into a single gang box which increases the possibility of physical contact between individual conductors or between the conductors and the gang box which may result in short-circuits. Also, the heat produced by these closely placed conductors may exceed safe levels.
One approach that reduces the crowding in the gang box and reduces the number of conductors for the switches is shown in U.S. Pat. No. 5,384,441 issued Jan. 24, 1995 and assigned to the assignee of the instant invention and by this reference incorporated into the instant application, makes use of a common phase conductor for each of the three rocker switches. Thus, the number of electrical conductors used in a gang box including such a switch arrangement is reduced to four. The number of rocker switch units, however, remains at three.
The instant invention overcomes one of the problems presented by the prior art by permitting the substitution of a single pole, double throw, center-off switch for one of the single pole, single throw on and off switches. The use of a common phase line for the two single pole, single throw switches permits these two switches to be wired using the three conductors of common three conductor cable and insures that the neutral return conductor is present in the cable to which the switches are wired.
The single pole, double throw, center-off switch can also be wired to the same three conductors used for the two single-pole, single throw switches. Thus, using the same three conductor cable, the number of switches has been increased to four. It is an object of this invention to provide a novel four function electrical rocker switch.
It is an object of this invention to provide a novel four function electrical rocker switch which can be placed within a single gang box.
It is an object of this invention to provide a novel four function electrical rocker switch which can be placed within a single gang box and wired to a single three conductor cable.
It is still another object of this invention to provide a novel four function electrical switch having two on/off single pole, single throw switches and a single pole, double throw, center-off switch.
Other objects and features of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principles of the invention, and the best mode which is presently contemplated for carrying them out.